Answer
The distance between the first two points is $\sqrt{10}$ units.
Work Step by Step
RECALL:
The distance $d$ between the points $(x_1, y_1)$ and $(x_2, y_2)$ is given by the formula
$d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$
Use the formula above to obtain:
$d=\sqrt{0-1)^2+(-6-(-3))^2}
\\d=\sqrt{(-1)^2+(-6+3)^2}
\\d=\sqrt{1+(-3)^2}
\\d=\sqrt{1+9}
\\d=\sqrt{10}$